334 ENTOMOLOGICAL NEWS. [DcC. , '05 



The Cambridge Entomological Club held an exhibition of insects on 

 Wednesday, Thursday, Friday and Saturday, November i, 2, 3, 4, at the 

 rooms of the Appallachian Mountain Club in the Tremont Building, 73 

 Tremont, corner of Beacon Street, Boston. The exhibition was similar 

 to that of last year, illustrating the insects of the neighboring country, life 

 histories, variation, insect injuries and other matters of general interest. 

 The exhibit was in charge of W. D. Denton, C. W. Johnson and J. H. 

 Emerton. 



The Migrations of Butterflies. — The great flights of butterflies, 

 which flutter by millions along some rivers in South America, have been 

 described by several travelers in the Amazon valley, but according to a 

 writer in the Reviie Scientifique , no one has yet succeeded in accounting 

 for them satisfactorily. An account of some recent observations, ab- 

 stracted from The Bulletin of the Para Museum, appears in the former 

 periodical (May 20). Says the writer : 



"The migrations of birds are well known, but those of butterflies do 

 not appear to be so generally recognized. M. Goeldi, the director of the 

 museum at Para, Brazil, gives some information about such migrations in 

 the Amazon valley, which are positively huge. The author states that 

 he was deeply impressed in 1870 by a migration of this kind, lasting 

 nearly an hour, which he witnessed in Switzerland, near Lake Neuchatel. 

 This was composed of an enormous number of individuals of Pieris 

 brassica. These pierides also made up the flight of butterflies in the 

 Amazon valley. 



" Such flights have been noted several times, especially by Bates, by 

 Spruce (in 1849), and also in an old Brazilian chronicle in 1615. But 

 some of the authors declare that the flights were southward and others 

 that they were northward. M. Goeldi has reconciled these stories; he 

 followed, on the Rio Capim, a flight of these myriads of butterflies, and 

 showed that the direction varied with the period of the journey. 



" The flights were composed exclusively of pierides, of which about 99 

 per cent, were Catopsilia statira and the rest almost entirely Eurema 

 albula. Goeldi took instantaneous photographs of the butterflies, of 

 which one is very interesting since it represents a passing irregularity in 

 the disciplined order of their flight; in certain places columns are detached, 

 make a detour, and rejoin the main body later, after describing a sort of 

 circle. 



" The excursionists who thus detach themselves temporarily, also do so 

 to direct their course toward a leguminous tree of frequent occurrence on 

 the banks of the Rio Capim. It is called in Brazil the arapary. 

 This tree at the time of the observed migrations (July-August) is in 

 flower, and the blossoms, though not visible to a great distance, give 

 out an intense perfume. The flower has a nectary to which the insects 

 resort to get the juice. It is always in the neighborhood of these trees 

 that the butterflies make their detours. The trees are very characteristic 

 of the river-banks of the Amazon basin, and must offer a highly prized 



